Environmental review completed for imidacloprid

Report evaluates impacts of using pesticide to control burrowing shrimp

Photo of Willipa Bay.

SOUTH BEND – After considering public input and conducting a thorough environmental assessment, the Washington Department of Ecology has completed the final environmental review on a proposal to use the pesticide imidacloprid to control burrowing shrimp.

Shellfish growers from Willapa Grays Harbor Oyster Growers Association (WGHOGA) have requested a permit to use the pesticide imidacloprid on burrowing shrimp in Willapa Bay and Grays Harbor. Ecology’s findings have been adopted in a formal report, called a Final Supplemental Environmental Impact Statement. This review adds to the initial Environmental Impact Statement adopted in 2015.

Supplemental environmental review findings:

Significant impacts to sediment quality and benthic invertebrates.

Adverse impacts to juvenile worms and crustaceans in the areas treated with imidacloprid and the nearby areas covered by incoming tides.

Concern about non-lethal impacts to invertebrates in the water column and sediment.

New information shows a risk of impacts from imidacloprid even at low concentrations.

Likely indirect impacts to fish and birds if food sources are disrupted.

Ecology will use these findings to inform the agency’s decision on the pending permit application. The agency anticipates announcing a decision in about a month.

The report compiles what Ecology learned by reviewing the best available science on this proposal and the public input received during a 45-day public comment period. Ecology received 8,287 comments on the draft of this report.
See the final report and learn more on our website at www.ecology.wa.gov/burrowingshrimp